Arbitrage Pricing Theory (APT) – Definition and Formula
A substitute and concurrent theory to the Capital Asset Pricing Model (CAPM) is one that incorporates multiple factors in explaining the movement of asset prices. The arbitrage pricing model (APT) on the other hand approaches pricing from a different aspect. It is rarely successful to analyze portfolio risks by assessing the weighted sum of its components. Equity portfolios are far more diverse and enormously large for separate component assessment, and the correlation existing between the elements would make a calculation as such untrue. Rather, the portfolio’s risk should be viewed as a single product’s innate risk. The APT represents portfolio risk by a factor model that is linear, where returns are a sum of risk factor returns. Factors may range from macroeconomic to fundamental market indices weighted by sensitivities to changes in each factor. These sensitivities are called factor-specific beta coefficients or more commonly, Continue reading